A method for the determination of malachite green(MG)，crystal violet(CV) and their metabolites residues leucomalachite green(LMG) and leucocrystal violet(LCV) in aquatic product was developed using QuEChERS combined with UPLC-MS-MS.The sample was extracted with acetonitrile and purified by EMR-Lipid.The target compounds were separated on an Agilent Eclipse Plus C18(1.8 μm,3.0 mm×100 mm) column,and detected by tandem mass spectrometry with electrospray ionization in positive mode.The linear ranges were in the range of 0.2-10.0 μg/L and the correlation coefficients were all above 0.997．The average recoveries of 4 analytes in fish matrix at three spiked concentrations of 0.5，1.0，5.0 μg/kg ranged from 77.1% to 106.6%,with relative standard deviations of 1.3%-4.3%．This method was simple and reliable，and could effectively remove the protein and fat in sample.Therefore,it is suitable for the determination of MG,CV and their leuco metabolites residues in aquatic product.